CVE-2026-28812 Apache JSPWiki: UserManager does not sanity-check user database at startup

Critical 9.8 Published 30 Jul 2026 Updated 31 Jul 2026

Attackers can impersonate users and escalate privileges due to missing sanity checks in the user database at startup.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-28812?

CVE-2026-28812 is a critical authentication bypass vulnerability in Apache JSPWiki, published on 30 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

UserManager lack of checks allows impersonation in Apache JSPWiki up to 2.12.3 which may allow attackers to escalate privileges. Users are recommended to upgrade to version 2.12.4 or newer which fixes this issue.

Weakness: CWE-290

Which versions are affected by CVE-2026-28812?

It affects 1 product.

Products include Apache Jspwiki.

How do I fix CVE-2026-28812?

No fix has been published for CVE-2026-28812 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-28812 being exploited?

There is no known exploitation of CVE-2026-28812 in the wild and no public exploit code.

Sources

Also known as GHSA-3qxc-7g4v-3gm9.